If oil enters the coolant, for example as a result of a defective cylinder head gasket, the radiator and expansion tank must be removed during repairs and washed with a BMW cleaning agent. Approximately 2 liters of cleaning agent are required for rinsing, follow the manufacturer's instructions for the operation. After installing the radiator, fill the entire cooling system repeatedly with hot water, after which the water is drained again. Since the cleaning fluid must not be drained onto the ground, it is recommended that the work be carried out by a BMW workshop.
Withdrawal
Remove the fan, see p. 38.
Drain the coolant according to the instructions in section "Maintenance work".
Loosen the clamps, slide them back and remove the coolant hoses at the top and bottom of the radiator.
1 - radiator
2 - expansion tank
3 - sealing ring
4 - sealing ring
5 - upper part of the tank
6 - cylinder head bolt
7 - expansion tank cap
8 - air removal plug
9 - plug for draining liquid
10 - temperature switch
Only with air conditioning.
11 - screw plug
12 - sealing ring
13 - liquid level sensor
14 - sealing ring
Detach wire from coolant level sender -13- at bottom left of radiator.
If there is an air conditioning system, disconnect the plug on the right side of the radiator from the temperature switch -10-.
If present, remove the automatic transmission oil cooler lines, collect the escaping transmission oil and clean it. Plug the pipes with clean plugs to prevent dirt from getting into them.
Attention: Coolers for power steering hydraulic system, air conditioning system and, as a rule, automatic transmission hydraulic systems are located in one holder (cassette) in front of the engine cooling radiator. To remove these refrigerators, you must first remove the radiator. The refrigerant circuit of the air conditioning system should only be opened by a specialist workshop with the appropriate equipment. Accident risk.
Remove sealing lips -1- towards top. Loosen left and right hexagon bolts -2- and remove both radiator brackets -3-.
Pull out the radiator upwards.
Attention: Radiator fins are sometimes very sharp, so gloves are recommended.
Installation
Check all coolant hoses for cuts, cracks or other damage, replace if necessary. Check the condition of both lower radiator rubber mounts.
Insert the radiator from above so that its supports sit exactly on the supporting surfaces.
Press the radiator against the bulkhead and install the mounting brackets. Put the sealing lips in place.
Screw automatic transmission oil lines with new O-rings to radiator and tighten to 20 Nm. Check transmission fluid level oil in the gearbox.
Fit the coolant hoses and tighten the clamps.
If removed, connect the wires of the temperature switch and the liquid level sensor.
Install fan.
Drink coolant and bleed air from the cooling system, see section "Maintenance work".
Warm up the engine and check the hose connections for leaks.
Check coolant level, top up if necessary.